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authorDan Carpenter <error27@gmail.com>2010-01-03 12:39:27 +0100
committerJaroslav Kysela <perex@perex.cz>2010-01-08 09:17:51 +0100
commit444c1953d496d272208902ff7010dc70d1f887f0 (patch)
tree40aa1e10f108818b3b7d12384229c0501aeb5a12
parent440b004cf953bec2bc8cd91c64ae707fd7e25327 (diff)
sound: oss: off by one bug
The problem is that in the original code sound_nblocks could go up to 1024 which would be an array overflow. This was found with a static checker and has been compile tested only. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
-rw-r--r--sound/oss/dev_table.c16
-rw-r--r--sound/oss/sound_config.h2
-rw-r--r--sound/oss/soundcard.c4
3 files changed, 13 insertions, 9 deletions
diff --git a/sound/oss/dev_table.c b/sound/oss/dev_table.c
index 08274c995d0..727bdb9ba2d 100644
--- a/sound/oss/dev_table.c
+++ b/sound/oss/dev_table.c
@@ -67,14 +67,15 @@ int sound_install_audiodrv(int vers, char *name, struct audio_driver *driver,
return -(EBUSY);
}
d = (struct audio_driver *) (sound_mem_blocks[sound_nblocks] = vmalloc(sizeof(struct audio_driver)));
-
- if (sound_nblocks < 1024)
- sound_nblocks++;
+ sound_nblocks++;
+ if (sound_nblocks >= MAX_MEM_BLOCKS)
+ sound_nblocks = MAX_MEM_BLOCKS - 1;
op = (struct audio_operations *) (sound_mem_blocks[sound_nblocks] = vmalloc(sizeof(struct audio_operations)));
+ sound_nblocks++;
+ if (sound_nblocks >= MAX_MEM_BLOCKS)
+ sound_nblocks = MAX_MEM_BLOCKS - 1;
- if (sound_nblocks < 1024)
- sound_nblocks++;
if (d == NULL || op == NULL) {
printk(KERN_ERR "Sound: Can't allocate driver for (%s)\n", name);
sound_unload_audiodev(num);
@@ -128,9 +129,10 @@ int sound_install_mixer(int vers, char *name, struct mixer_operations *driver,
until you unload sound! */
op = (struct mixer_operations *) (sound_mem_blocks[sound_nblocks] = vmalloc(sizeof(struct mixer_operations)));
+ sound_nblocks++;
+ if (sound_nblocks >= MAX_MEM_BLOCKS)
+ sound_nblocks = MAX_MEM_BLOCKS - 1;
- if (sound_nblocks < 1024)
- sound_nblocks++;
if (op == NULL) {
printk(KERN_ERR "Sound: Can't allocate mixer driver for (%s)\n", name);
return -ENOMEM;
diff --git a/sound/oss/sound_config.h b/sound/oss/sound_config.h
index 55271fbe7f4..9d35c4c65b9 100644
--- a/sound/oss/sound_config.h
+++ b/sound/oss/sound_config.h
@@ -142,4 +142,6 @@ static inline int translate_mode(struct file *file)
#define TIMER_ARMED 121234
#define TIMER_NOT_ARMED 1
+#define MAX_MEM_BLOCKS 1024
+
#endif
diff --git a/sound/oss/soundcard.c b/sound/oss/soundcard.c
index 61aaedae6b7..c6253094388 100644
--- a/sound/oss/soundcard.c
+++ b/sound/oss/soundcard.c
@@ -56,7 +56,7 @@
/*
* Table for permanently allocated memory (used when unloading the module)
*/
-void * sound_mem_blocks[1024];
+void * sound_mem_blocks[MAX_MEM_BLOCKS];
int sound_nblocks = 0;
/* Persistent DMA buffers */
@@ -574,7 +574,7 @@ static int __init oss_init(void)
NULL, "%s%d", dev_list[i].name, j);
}
- if (sound_nblocks >= 1024)
+ if (sound_nblocks >= MAX_MEM_BLOCKS - 1)
printk(KERN_ERR "Sound warning: Deallocation table was too small.\n");
return 0;